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arXiv · 1403.6961

Is the first excited state of the $α$-particle a breathing mode?

Sonia Bacca·Nir Barnea·Winfried Leidemann·Giuseppina Orlandini
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Abstract

The isoscalar monopole excitation of 4He is studied within a few-body ab initio approach. We consider the transition density to the low-lying and narrow 0+ resonance, as well as various sum rules and the strength energy distribution itself at different momentum transfers q. Realistic nuclear forces of chiral and phenomenological nature are employed. Various indications for a collective breathing mode are found: i) the specific shape of the transition density, ii) the high degree of exhaustion of the non-energy-weighted sum rule at low q and iii) the complete dominance of the resonance peak in the excitation spectrum. For the incompressibility K of the alpha-particle values between 20 and 30 MeV are found.

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Sonia Bacca, Nir Barnea, Winfried Leidemann, Giuseppina Orlandini. 2014-03-27. Is the first excited state of the $α$-particle a breathing mode?. https://doi.org/10.1103/physrevc.91.024303

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